Expansion piston



May 24,1921 G, w, BooKSH EXPANSFI ON TPI STON `Fi1ed Oct. 20, 1926 2 Sheets-Sheet l G. W. BOOKSH EXPANSION PISTON May 244., 1927. 1,629,988

Filed Oct. 20. 1926 2 Sheets-Sheet 2 f5 z 27 i Z5 gru/vanto@ @ewige WZM/d GEORGE BOOXSH, OF G ROSSE TETE, LOUISIANA.

This invention relates to 'PATENT OFFICE..

EXPANSION PISTON.

Application tiled October 20, 1926. Serial No. 142,937.

pistons for engines such as internal combustion motors and has special piston.

reference to an expansible One important object of the invention is to provide an improved form of piston capable of being expanded so as to take up any wear which may occur either in the Apiston or the cylinder in which it moves.

A second important object of the invention is to provide a novel be expanded so as to fit closeness that the rings, comwhich may inder to such form of piston its cyl- ,inon to pistons, are rendered unnecessary and maybe eliminated.

A third important '.is to so arrange that the expansi tially no distortion of the piston from With the above and other ob] object of the' invention the parts of such a piston on is eifected with substanthe cross section of a true circle.

ects in view as will be hereinafter apparent, the invention consists in general of construction claimed.

In the accompanying of certain novel details and combinations of parts described, illustrated in drawings and specifically drawings like characters of reference indicate like parts in the several views, and:

Figure 1 is a side elevation of a iston constructed in accordance with this invention.

Figure 2 is a Figure 1.

Figure 3 Figure 2.

is a

V*of Figure 1.

Figure 5 is -a section on the line 2-2 of section on the 4line 3-3 of re 4 S detail section on the line 4-4 section through one of the side walls showing the dovetail lugs.

Figure 6 is a detail view of one of the tapered bolts used herewith.

This inventioninc hides a 'pair of what are preferably termed side walls 10 and a pair of wedge 'members 11 which iit between the inclined inner surfaces 12 of the side walls.v These parts are` dovetails 13.

About cent-rally of the length of the piston on each side wall is the edges of t e air of lu s 14 which are spaced from wedge walls 11 and between i these lugs and the edges of said wedge walls are mounted tapered bolts 15 which terminate at the open 16 each passing end of the piston in a shank through a lug 17 `carried on4 held together by y a yrespective side wall. The lower end of each shank is threaded as at 18 and on this threaded end is screwed a nut 19 which bears against the underside of the lug 17 so that, by screwing up upon the nuts the wedges are drawn down and the Wedge walls 11 forced outwardly. Due to the dovetailing and to the fact that the side walls are vthinner toward their ends than at the middle the outward movement of the wedge walls 11 forces vthe ends of the side walls further apart and thus expands the piston in a sub-l run back into the hollow cylinder and drop into the crank case. It will be observed that between the nut 19 and'lug` 17 there is pro'- vided a spring 22 on each wedge so that proper tension can be maintained on the wedges. The upper ends-of the side and wedge walls are provided 'with' internal flan e portions 23 beneath which is engaged a p ate 24 and, on top of these side and wedge walls is formed any annular boss or ring 25 whereon rests a. plate 26. A bolt and nut 27 serves to hold these two plates together and the plates closure for the piston. Obviously the bolt must not be clamped so tightly as to interfere with the action of the wedges while at the same time it must be clamped ti htly enough to cause the plates to lit closely on the parts. The wedge walls are preferably provided with the usual cranky pin openin s 28.

here has thus been provided a simple and efficient device of the kind described and for the purpose specified: 1

It is obvious that minor changes may be made inthe form andcoiistructionnf the invention without departing from the material spirit thereof. It is not, therefore, de-y sired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

thus form the end Having thus described the invention, what is claimed as new is: Y

1. A piston including a body consisting of a pair of side wall segments diametrically opposed and having inside edge surfaces inclined on each segment towards the corres onding surfaces of the other segment, said body havingwedge wall segments each fitted between a corresponding pair of said inclined surfaces and dovetailed thereto, said side wall segments having lugs thereon spacedfrom the lateral inner edge portions of the edge wall segments, wedges extending longitudinally of the piston between said lugs and lateral edge portions, and means to adjust said wedgesl longitudinally and thereby force the wedge wall segments apart whereby to spring the edge portions of the side wall segments outwardly.

2. A piston including a body consisting of a pair of side wall segments diametrically opposed and having inside edge surfaces inclined on each segment towards the corresponding surfaces o'f the other segment, said body having wedge wall segments each fitted between a corresponding pair of said inclined surfaces and dovetailed thereto, said side wall segments having lugs vthereon spaced from the lateral inner edge portions of the wed e wall segments, wedges extending longitu inally of the piston between said lugs and lateral edge portions, and means to adjust said wedges. longitudinally and thereby force the wedge wall segments apart whereby to spring the edge portions of the side wall segments outwardly, said means including springs to maintain the wedges in adjusted position under tension.

3. A piston including a body consisting of a pair of side wall segments diametrically opposed and having inside edge surfaces inclined on each segment towards the corresponding surfaces of the other segment, said body having wedge wall segments each fitted between a corresponding pair of said inclined surfaces and a dovetailed thereto,

said side wall segments having lugs thereon spaced from the lateral inner edge portions of the wedge wall segments, wedges extending longitudinally of the piston between said lugs and lateral edge portions, means to adjust said wedges longitudinally and thereby force the wedge wall segments apart whereby to spring the edge portions of the side wall segments outwardly, and an end closure for said body having said segments slidably connected thereto.

4. A piston including a body consisting of a pair of side wall segments diametrically opposed and having inside edge surfaces inclined on each segment towards the corresponding surfaces of the other segment, said body having wedge wall segments each fitted between a corresponding pair of s'aid inclined surfaces and dovetailed thereto, said side wall segments having lugs' thereon spaced from the lateral inner edge portions of the wedge wall segments, wedges extending longitudinally of the piston between said lugs and lateral edge portions, means to adjust said wedges longitudinally and thereby force the wedge wall segments apart whereby to spring the edge portions of the side wall segments outwardly, said means including springs to maintain the wedges inadjusted position under tension, and an end closure for said body having said segments slidably connected thereto.

5. A piston including a body consisting of a pair of side wall segments diametrically opposed and having inside edge surfaces inclined on each segment towards the corresponding surfaces of the other segment, said body having wedge wall segments each fitted between a corresponding pair of said inclined surfaces and dovetailed thereto, said side wall segments having lugs thereon spaced from the lateral inner edge portions of the wedge wall segments, wedges extending longitudinally of the piston between said lugs andlateral edge portions, means to adjust said wedges longitudinally and thereby force the wedge wall segments apart whereby to spring the edge portions of the side wall segments outwardly, said means including springs to maintain the wedges in adjusted position under tension, internal flanges on the head ends of said segments, a plate within the body engaging said fianges, a second plate resting on top of the flanges, and a bolt and nut connecting said plates.

In testimony whereof I aiiix my signature.

GEORGE W. BOOKSH. 

